18211165065 has 32 divisors (see below), whose sum is σ = 32695977600. Its totient is φ = 9616449600.

The previous prime is 18211165043. The next prime is 18211165067. The reversal of 18211165065 is 56056111281.

18211165065 is a `hidden beast` number, since 18 + 21 + 116 + 506 + 5 = 666.

It is not a de Polignac number, because 18211165065 - 2¹⁸ = 18210902921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18211165067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 654175 + ... + 681444.

It is an arithmetic number, because the mean of its divisors is an integer number (1021749300).

Almost surely, 2^18211165065 is an apocalyptic number.

18211165065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18211165065 is a deficient number, since it is larger than the sum of its proper divisors (14484812535).

18211165065 is a wasteful number, since it uses less digits than its factorization.

18211165065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1335734 (or 1335728 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

The spelling of 18211165065 in words is "eighteen billion, two hundred eleven million, one hundred sixty-five thousand, sixty-five".